Process and apparatus for forming and annealing sheet glass



c. CONE 1,848,161

PROCESS AND APPARATUS FOR FORMING AND ANNEALING SHEET GLASS March 8, 1932.

Filed Sept. 18, 1929 gwwnkw Car/ ol/ Cane I Patented Mar. 8, 1932 7 CARROLL com; OF'TOLEDO,

onto, AssIG oR To, r rniany ownns ronn Gnhss-coMPAnY;

' or monnno, meg consu a on01m rnocnss ANDILAPPIARA'ITUS non roma ne m A mnALING snnn'r qL-iessff-C .A ncationjmed.septen ber'1s,.,192a; seria1'iwoaseajtei,

v Thelpresent invention rela tesfjto ianf ing operation. after which said sheets ar gradually reduced in temperature by passing themthrough :an anneallng leer. It is desirable, in order to increase production improve the quality of the 'glass'&sheets, 'that' theyibe formed at a relativelyhigh rate ofi I speed such as forexample, approximately sixty feet per minute, although this speed I I maybe increased ordecreased' if'preferred.

' A considerable length of time is ordinarily required'to properly 'a'nnealthe' glass sheets and were the sheet carried entirely through c the leer at th'e same high'rate'fof speed at whichit was formed, it will beapp'arentthat I II men" will become rnore apparent during the course ofthe 'follo'wing description when; taken in connection with the-accompanying I L the leer "would necessarily have to be Iofconfsiderable length." However, is preferred, although not necessary, thatjthe "glass be kept in constant motion after being for ned until it is properly annealed or at least; until it has becomesubstantially set. j

The obj ect of this invention' broadly stat:

ed; is in the provision of a processand appa- I ratus wherein the glass sheets nay beformed at a relatively high rate ofspeed' and subsequently continuously annealedfwhile traveling'at a speed relatively" less than its speed of formation. Thus, the process and' apfparatus herein provided will embody those advantages incident" to therapid reduction of the molten glass to sheet form and likewise, thoseadvantages'which result from slower I annealing of the glass. I j

' Anot-her objectof the invention resides in tus wherein successive sheets of glass are formed and carried continuously forwardly into and through an annealing'le'er, the glass sheet being caused to travel at vvariable speeds in sucharnanner as to prevent sagging of the sheet; therebyi-mproving the quality ofthe glass and facilitatingthe an In the drawings "forming a"; of this posited. upon thereceiver 5 whenthe same is the provision of sucha process and apparav in a substantially horizontal .p'ositionas indi- 'wherein the speedlo f travel of the sheet into "and through theiannealing leer vis'varied at 'predetern ined intervals in such "a I inanner that the forwardend', of each sheetflfornied I will closely. adjacentgthe rear end of the precedingsheet. assaid sheets pass through the annealingleer, to the end t'hat theleer' 1 c v 7 may be u-tilized-toits fiill capacityand thus mi e large ps t e :ihf ts:

I A furthei l objectgof the" invention is to pro; vide: such a process Land. apparatus wherein the glass sheet is formed at a r'elativelyhighrateofspeed after which the speed or. travel of the sheet is decreased to. an intermediate speed during the remainder of the sheet form ing cycle and then further decreased wan annealing speed, the {sheet ,being passed through the, anneali leer a c r n II II V .speed.,

,Qtheri advantages :oif the invend i s- 1 a.

application and wherein like numerals are employed to designate like parts throughout thesaine; I I

Figs lis' av vertical; longitudinal section through; apparatus provided; by the present nve i -1; a 5 ,c; c i Fig.2'is a top'planvie-w thereof and" Fig. 3' is, a vertical longitudinal section. of an;alternate arrangeinent.

v Referring to the drawings and particularly e. to Figs. land 25 the numeral 5 designates a receiver or support for receiving thereupon} a mass of molten glassG to bereduced t'o sheet form. :Themolten glass ,6 is-preferably de-- cated-by thegbroken lines in 1, after which saidre'ceiver is tilted tojits full line 5 position so that the "niolten glass" will be moved therefroin between the substantially superimposed sheetforrning irolls 7 an d 8 as V nealing thereof; I II I II I I I II I Another object of the inventionjisin the sheet .9 iss ing Ii fO Il :b 'tw h g orm ng I provisienr 1 1 a Pr c s [a d pn re sel s. 7 a 3 isf ess isl l'l i jfe i 1 2 13 63 said section is speeded up to receive the fol runway 10 which functions to guide and support the sheet during its inclined downward travel- The forming rolls 7 and 8 serve to reduce the molten glass 6 to a sheet of substantially predetermined and uniform thickness and the spacebetween the forming rolls determines the thickness of sheetproduced.

It is desirable, as pointed out above, that the glass-sheet beformed at a relatively high rate of speed and the forming rolls 7 and S are therefore rotated in a mannerthat their peripheral speed will be such that they Wll'l act to rapidly reduce the molten glass 6 to sheet form. One of the formingroll's is preferably positively driven such as through a chain drive 11 and the other forming roll is driven from the positively driven roll by means of intermeshing'gears 12 carried by therollshafts.

Positioned to receive the sheet 9 from the inclined runway 10.is conveyor table 13 constituting a transfer section'and which is composed of a-plurality of" horizontally arranged rolls'l't carried by shafts Which are rotatably mounted within the side members and 16 supported'by the vertical uprights 1-7. 1 The rolls 14: are adapted to be driven in unison at thesame speed, andthis-may be accomplished in any preferred-1 manner" such as by keying to each ro-ll shaft a sprocket (not shown) and training about the sprockets a sprocket chain 18 driven from avariable speed motor 19. v j

Arranged at the end of the transfer section, 13' is aleer 2O within whiclrare arranged a: plurality of rolls 21 is horizontal alignment with rolls 14- of-section 13. The rolls 21 are also adapted to be rotated in unison but independently of rolls 14: by the provision of a chain drive 22 driven from a variable speed motor-23.

In operation, the mass of molten gl'ass6 is first deposited upon the receiver 5 and sub sequently passed to the forming-rolls 7 and 8" which serveto reduce the glass to a sheet 9 of substantially predetermined and uni formthickness. During-theformation of the sheet, the rolls 14 of transfer section 13 are being driven at a speed equal tothespeed of the-forming rolls and-8 As the sheet issues from the rolling machine, it is received upon and-travelsoverthe rolls 14 until the head or forward end of the sheet reaches the endof the transfer section 13. The transfer rolls 14 and leer rolls 21 are then synchronized at anintermediate speed which is less than the rollingspeed and just sufficient to carry the sheet off the-transfer rolls during the remainder of the sheet formingcycle. As soon a'sthe tail of'the sheet leaves the section 13,

lowing sheet and at the same time the leer rolls are dropped to a very low speed, only fast enough to keep the sheet from acquiring a permanent deformation and are kept at this Transfer speed speed until it is again necessary to synchro nize them with the transfer rolls to receive another sheet. In other words, the leer rolls are intermittently driven first at a high speed equalsto the low speed of the transfer rolls and then at a slower annealing speed, while-the transfer rolls are driven intermittently first at the rolling speed and then at alow. speed. equalto the high speedof the leer rolls. By the term sheet forming cycle is meant that time which is required from the beginning of the rolling of onesheet to the beginning of the rolling of the next sheet and thisais usualflyap proximately seven minutes.

While the present invention is not to be limited to any specific "speeds setforth herein, the followingexample isgivenmerely by way of illnstration to'render the invention more fully-understood. Forexarn-plemssum- V I -85 ling? Sheet forming cycle; Q 7 minutes. R,o11ing -speed feet per minute. Length-ofisheeh; 100 feet... Length. of transferzsectionifl 150-feet.

Rolling time 2 ,1 minutes.

22.2 feet per minute.

Transfer time 4. minutes.

Leerspeed 2feet per minute.

Gap between sheets in leer 5 feet;

7 From theabove example, it will be readily understood that ifa glass, sheet 100. feet in length, was rolled at the rate, of 60 feet per minute andcarried forwardly atthi's speed, it would require 2, minutes for the forward end of-theesheet to reach the. end of transfer section l3 Whichis 150 feet long. TWhen the forward end ofthe sheet reaches the end of the, transfer section, the speed ofthe transfer roll's is reduced and the speed of the leer rolls 21. increasedso that the said rolls are synchronized at the intermediate transfer speedof 22.2 feet" per minute during the remainder of the cycle of seven minutes so that the transfer of' the sheet into the leer will require minutes. After'the sheet is entirely in the leer, the speed. of the leer rolls 21 speed of the sheet were reduced from, sixty feet per minute immediately to two. feet per minute, a larger gap would be formed at the same minimum speed and there might also be atendency for the sheet to sag beforebecoming; substantially set. With the present invention, however; the sheet is' kept at a com- 'plete rollingcycle which gives several min-v utes for the glass 'to set before it is subjected paratively high speed throughout the comto drastic changes in speed or is compelled to support its weight over the rolls at a very low speed. Also, large gaps between the sheets which would result in the leer from a continuously high leer speed are avoided without complicated selective control of theindividual rolls. The layout above described maybe made sufiiciently flexible to permit a Wide range of speeds.

The form of Fig. 3 is substantially the same as described hereinabove with the principal exception that a the transfer section is also arranged within the leer. In other words,'there is provided a leer 24 within whichare arranged a large number of horizontally aligned rolls 25. The rolls 25 within the leer are divided into two unitsor sections A and'B, the section A being the transfer section and B, the annealing section. Thus, the rolls of transfer section A are dropped to a very low speed and kept at this speed until it is again necessary to synchronize them with the transfer rolls to receive another sheet therefrom. c

It is to be understood thatthe form of the invention herewith shown and described is to be taken as thepreferred embodiment of the same, and that various changes in the shape,

. size and arrangement of parts may be resorted to without departing from the spirit'of the invention or the scope of the subjoined claims.

I claim 1. In glass apparatus, sheet forming means,

an annealing leer, and conveying mechanismv for receiving the sheet from the forming means and carrying it into and through said leer including a'transfer section, means for driving said section at variable speeds, an annealing section, and separate means for driving said annealing section at'variable speeds.

2. The process of producing sheet glass,

which consists in first forming the sheetat a predetermined rate of speed, in carrying the sheet forwardly into an annealing chamher and progressively decreasing the speed of travel thereof, and in annealing the sheet while causing it to travel through said chamber alternately at a relatively high speed and then at a relativelyslower'speed.

3. The process of producing sheet glass, which consists in first forming the sheet at the invention illustrated in travel of the'shee't and feeding it at such re-.

duced speed into an annealing chamber, again reducing the speed of travel of the sheet after it is received within the chamber, and

in alternately increasing and then decreasing the speed of travel of thesheet during its passage through said chamber.

4:; The process of producing sheet glass, which consists in forming a plurality o 1 suce cessive sheets of glass at predetermined inter- 'vals' and at'a relatively high rate of speed,

carrying eachsheet forwardly as it is formed intoan annealing chamber, reducing the speed of travel of the sheet whenit is received I within the annealing chamber, and in 7 thenagain increasing the speed of travel of the sheet to a' speed relatively less than that of sheet formation during the transfer of each succeeding sheet formed into said'annealing. chamber.

5. Theproc'ess of producing sh-eet'glass,

which consists informing a lplurality of sue-'- v cessive sheets of glass at predetermined intervals and at a relatively high rate of speed,

carrying each sheet forwardly after it is formed, 'reducing" the speed of fltravel thereof and transferring it at such speed into an annealing chamber, again reducing the speed oftravel of the sheet whenit is rei V ceived within the annealing chamber, and in then again increasing'the speed of travel of the sheet-to a speed equal to the intermediate speed during the transfer of each succeeding 7 sheet formed into said annealing section. 1

6. The process of producing sheet glass,

which consists in forming the sheet at a relatively high rate of speed and delivering it at such speed onto a conveying mechanism,

reducing the speed of travel of the sheet when upon said conveying mechanism and transferring 1t at such reduced speed onto a second conveying mechanlsm, decreasing the speed of-the second conveying mechanism when the sheet is received thereon andin increasing the speedofthe first conveylng mechanism,

and in annealing the sheet while causing it .to c be carried forwardly'upon said second conveying mechanism alternately at a relatively high speed which is equal to said transfer speed and then at a relatively slower speed. S1gned at Toledo, in the county of Lucas and State, of Ohio, this 30th day of August,

' CARROLL CONE.

a predetermined rate of speed, carrying thesheet forwardly at a speed equal to the speed i I of formationthereof, reducing the speed of J 

